Brush for dynamo-electric machines.



E. T. MUG.

BRUSH FOR DYNAMO ELECTRIC MACHINES APPLICATION FILED NOV. 17, 1906.

Patented J an. 5, 1909.

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Edward BY TTDRNE'Y- -EDWARD T. MUG, OF

NORWOOD, OHIO, ASSIGNOR TO THE BULLOCK ELECTRIC MANLFAC- URING GOMPANY. A CORPORATION OF OHIO.

BRUSH FOB DYNAMO-ELEGTRTC MACHINES.

pecification of Letters Patent.

Patented Jan. 5, 1909.

Application filed November 17, 1905. Serial No. 287,833.

To'czZl whom it may concern:

Be it known that I, EDWAItD T. MUG, citizen of the United States, residing at Nor- HQLO wood, in the county of Hamilton and State of Ohio, have invented certain new and usefnl Improvements in Brushes for Dynamo- Electric Machines, of which the following is a I full, clear, and exact specification.

My invention relates to brushes for dyname-electric machines, and more partlcu larly to the connections between the brushes and flexible leads or conductors.

Heretofore, great difficulty has been experienced in cifec'ting a good electric and mechanical connection between the high resistance brush ordinarily employed in dynamoelectric machines and the low resistance, braided flexible conductor or pig tail con nected thereto. The flexible conductor has been connected to the carbon brush in a reat many ways, for instance, by soldering it directly to the copper plated surface of the brush; by soldering it 1n a slot formed in the brush; by'fastening it to a bolt placed in a transverse hole drilled through the brush; by clam ing and soldering it to a metallic clip whic is then in turn soldered to the copper plating of the brush, etc. Soldered connections are objectionable on account of the liability of the very thin copper coating becoming oxidized by the heat of soldering and the connection between the conductor and the brush being thereby loosened, even entirely destroyed. The other methods above enumerated are objectionable for the reason that they require a multiplicity of parts which are expensive to construct and assemble.

1) of the conductor and fills the unoccupied s pace in the channel, whereby a good connectron electrically and mechanically is obtainedf More specifically considered my invention consists of a brush having a transverse channel and one or more openings extending from the top of the brush into the channel and into the body of the brush if desired, a flexible conductor extending through each of the openings into the channel, and a fusible metal filling the unoccu ied space in the channel and openings and holding the conductors in place.

My invention still further consists in the details of construction and combinations of elements described in the-specification and set forth in the appended claims.

I will now explain my improved connection, and also the steps of the process of the formations of the same by reference to the accompanying drawings in whioh Figure 1 is an elevation of a brush provided with my invention, parts beingbroken away for the sake ofclearness; and Fig. 2 is a side view of the same.

Referring'now to the figures of the draw ing, I have shown at 10, a carbon brush as ordinarily used in dynamo-electric machines. The carbon brush is provided at 11 and 11 with two flexible braided wire conductors or pig tails attached to the brush by my iniprovedconnection. The brush is provided near its .top with a transverse channel or perforation 12 extending from side to side of the brush, and also with the two openings or channels 13 and 13 which are arranged at right angles to the channel 12 and extend from the top of the brush to the channel. The perforations or channels 12, 13, and 13 may be formed in the brush during the process of its manufacture or may be afterwards drilled. If desired, the channels or openings 13 and 13 may extend beyond the transverse channel 12, into the body of the brush.

Preferably flat, woven wire, flexible 0011-, ductors, or pig tails, 11 and 11 are employed. The lower ends of these conductors are turned or rounded as shown and extend from the top of the brush through the channels or openings 13 and 13 into the channel 12. The free ends of the conductors which extend into the channel 12 are preferably bent by a suitable tool in the direction of the channel, and preferably toward each other, as shown. I have shown two channels leading from the top of the brush to thetransverse channel 12, and I have shown two conductors 11 and 11 with their ends inserted therein, but IWisl'i to beunderstood not to be confined to the use 0 number of conductors shown.

the same current carrying cepacity much more flexible pigtails can be employed than it a single large pig ml or conductor is employed.

After the ends of the conductors are inserted in place in the brush, o iusible meta or alloy 14, such as Babbitt, or type motel, run into the channel 12, until the-Lino "cupied space in all the openings is entirely inn-d end the ends of the conductors are completely surrounded by the medal. is seen that when the metal 1-1 is cooled and hardened that a connection is formed between the brush and the conductor or conductors which is most effective, both electrically chanically. It will be in possible for the conductors to become loose accidentally. ll de sired, a fusible anchoring metal or alloy Ll may be employed which will expend on solidifying to more completely till the space in the brush. The channels 13 and 135 may extend beyond the transverse channel l2 into the body of the brush as far a" desired. In this case the "fusible metal would provide a better path for the currcnt tlnm the carbon and therefore the resistance and conseouent 1 I v r l 3 Of llOlPS Q1 openings l l l l 1 heating would be reduced and life of the brush prolonged. The ends of t conductors are provided with connection clips 15 iii-ado ol flexible punched material by means of which the con i ductors may be connected to a brush hold r or any other stationary member. I i do not Wish to be conlincd to the details shown, 1' have shown- :1. preferred embodil rncnt ol' my invontim'i, but various changes i may be made without departing from the; 5 int and scope of my invention and l aim in l the appended claims to cover all such changes l and modifications.

Having thus described my invention, wht I claun as new and desire to secure by Letters Patent is 1. A carbon brush haying a transverse channel. and channel or opening cntcndin I from the transverse channel to the top of the l brush, a l'usiblc rnctal filling said channels, l and a conductor embedded in said metal. l

llllil ceroon bl:

.Xtendin the the transvers trai in the alloy consisting of pends on solidifying.

A carbon brush channel extending: tber i ez-itenuir' the brush to said channel, tor extending through co into the cha ncl, ".d e. fusible channel completely surround ing the conductors in place.

A brush having a citending' therethrc ings or channels leadh 

